Asian Food Science Journal

This study investigates the effect of white and black Piper nigrum and Piper guineense on lipids quality of oil extracted from groundnuts pudding. This work was carried in the Research Unit of Biochemistry, Medicinal plants, Food Sciences, and Nutrition, Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon, between January 2018 and December 2019. The antioxidant activity of these spices was determined. Cooking by steaming of groundnuts (Arachis hypogaea) pudding was carried out using groundnuts paste with 0 g, 0.5 g, 1 g, 2 g and 4 g of spices and 30 ml of warm water respectively. Oils were extracted from the prepared groundnuts pudding using a mixture of chloroform and methanol. The lipid quality of oil samples was studied by the determination of the peroxide, P-anisidine, total oxidation, thiobarbituric and iodine values. Results revealed that these spices possess non negligible antioxidant properties. Black Piper nigrum (BPN) presented the highest total phenolic (TPC: 85.00 mg GAE/g) and flavonoids (FC: 271.94 mg CE/g) contents. The lowest TPC and FC was observed with the aqueous extract white Piper nigrum (WPN: 52.38 mg GAE/g and 113.32 mg CE/g respectively). The use of these spices in groundnuts pudding preparation contributed to limit the formation of primary and secondary oxidation products of groundnuts pudding oil. It was also observed that white Piper nigrum (WPN) better preserve lipids quality of oils at all concentrations because oil extracted from pudding cooked with 0.5 g, 1 g, 2 g and 4 g presented peroxide values lower than 10 meqO₂/kg (2.81 meqO₂/kg, 2.99 meqO₂/kg, 3.28 meqO₂/kg and 5.46 meqO₂/kg respectively). In summary these spices especially white Piper nigrum can be used to preserve lipids oxidation during cooking by steaming of groundnuts pudding.